1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26+27+28+29+30+31+32+33+34+35+36+37+38+39+40+41+42+43+44+45+46+47+48+49+50+51+52+53+54+55+56+57+58+59+60+61+62+63+64+65+66+67+68+69+70+71+72+73+74+75+76++77+78+79++80+81+82+83+84+85+86+87+88+89+90+91+92+93+94+95+96+97+98+99+100=????????????????????????????????????????????????????????????????????????
A= 1+2+3+4+….+100
= ( 1+100).[( 100-1):1+1]:2
= 5050
Đáp án:
Giải thích các bước giải: